The Calamity of the Six Worlds.
It happened tens of millions of years ago.
By chance, the Nefarious and Demon Realms obtained a Holy Weapon and suddenly launched an attack, seeking to destroy the other four realms and expand their own territory.
After all, the Immortal and Divine Realms were the most suitable realms for cultivating immortality.
After countless years of war across the six worlds, and after the sacrifice of innumerable powerful experts, the Nefarious and Demon Realms were finally sealed away in a place utterly devoid of spiritual energy.
This place came to be known as the Nefarious Demon Region.
It was precisely this great calamity of the six worlds that caused the human race to lose several Human Ancestors.
Which led to the Mortal Realm's strength falling without end.
Later on, no one was able to ascend to the position of Human Ancestor, which resulted in the Mortal Realm being countless times weaker than the other three realms.
